EPA grants registration for new Strada rice herbicide

Isagro USA, Inc., isn't exactly a household name in U.S. farming circles. But the Italian-owned company appears to be poised to take on a more visible role in the U.S. crop protection chemical business.

Isagro USA, a subsidiary of Isagro SpA in Milan, has received a Section 3 registration for Strada herbicide for use in rice. Strada, which means path in Italian, provides broad-spectrum control of broadleaf, sedge and aquatic weeds, including hemp sesbania, northern jointvetch, yellow nutsedge and ducksalad.

Strada WG will be available for Mid-South rice growers in 2007. Strada GR, a granular formulation for applications into the flood, will be available for 2008. California registrations for both are expected in late 2007.

While Isagro USA, which is headquartered near Research Triangle Park, N.C., might not be as well known as other U.S. and foreign manufacturers, the company and its predecessors have been around awhile, according to Mark Quick, national sales and marketing manager for Isagro.

“We are a discovery-based company with 30 years experience,” said Quick. “Besides the fungicide Domark, for which we expect Section 3 registration from EPA this year, we are also the No. 1 producer of copper-based fungicides. We have a number of other products in our pipeline.”

Strada's active ingredient is orthosulfamuron, a sulfamoylurea that is an acetolactate synthase (ALS/AHAS) inhibitor. As with other sulfamoylureas, Strada herbicide inhibits the production of branched-chain amino acids found only in plants.

During five years of testing in all rice growing areas in the United States, Isagro and university scientists and consultants have learned even more about the herbicide, says Chris Leon, who works in product development for Isagro USA out of Madison, Miss.

“Besides showing excellent crop safety, Strada is a perfect fit in a program approach with clomazone, quinclorac, imazethapyr and propanil,” he said. “Strada fills the voids or weaknesses in broadleaf and aquatic weed control that those products miss.

“Strada is most impressive when used in a program approach with clomazone followed by propanil plus Strada.”

Strada, which will be packaged in 42-ounce bottles, can be applied postemergence in dry and water-seeded rice. Rates will be 1.7 to 2.1 ounces of product per acre, according to Leon.

Researchers have found Strada works best following a residual herbicide such as clomazone (Command), imazethapyr (Newpath) or quinclorac (Facet) or in a total postemergence program with those products or with propanil-based products. Permanent flood should be established within 10 days of application.

Strada used in conjunction with those herbicides consistently provides better than 90 percent control of hemp sesbania (92 percent), annual sedge (94 percent), eclipta (95), spreading dayflower (91), morningglory species (93) and Pennsylvania smartweed (89) with almost no injury to the rice.

Researchers have also observed yield increases of 10 bushels per acre when Strada was applied in combination with those products. In trials at Texas A&M University's Rice Research Station at Beaumont, Texas, yields have ranged up to 22 bushels per acre higher with Strada versus a competitor.